1. Technical Field
The present disclosure is related to air-driven shutter devices and optical analyzers.
2. Background Information
Conventionally, in optical analyzers, a fail-safe mechanism is provided to reduce or eliminate damage from anomalous operation. Such a device is disclosed in the specification of U.S. Pat. No. 7,469,717, which provides a fail-safe shutter. The fail-safe shutter includes a gate that slides over a round hole to cover or close the hole. The gate is urged by a spring to close the hole, and a clutch is connected to the gate to transmit the power from a motor. Accordingly, when power is supplied to the motor, the hole is opened. In contrast, when the power fails to be supplied, the clutch is disengaged, and the gate is urged by the spring so that the hole is covered.
In the prior art fail-safe shutter described above, the electric power always has to be supplied to the motor, and a control circuit is provided for controlling the electric power. That is, the configuration of the fail-safe shutter becomes complicated, and it is necessary to provide the motor and the control circuit, which results in the shutter being expensive. In addition, the constant electric power supply is not preferable in light of energy conservation.